ES2525790T3 - Thick suspensions of stratified silicates with a high content of solid materials - Google Patents

Abstract

Thick suspension or respectively sludge, containing a) at least 10% by weight of at least one layered silicate chosen from the set of smectites, chosen from the set consisting of a montmorillonite such as a bentonite and a land of batan, a hectorite, an antigorite, a nontronite, a beidellite, a saponite, of the set of vermiculites, of the set of illites or of micas, as well as a sepiolite, an attapulgite (paligorskite), a stevensite or a chlorite, referred to the total weight of the thick suspension or respectively of the sludge; b) an aqueous suspension medium; c) an auxiliary dispersing agent chosen from at least one poly (ethylene glycol) having an average molecular weight of less than 90,000.

Description

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

E06762361

11-12-2014

DESCRIPTION

Thick suspensions of stratified silicates with a high content of solid materials

The present invention relates to a thick suspension or respectively to a sludge that is based on stratified silicates with a high content of solid materials, a process for its production and its use.

For some technical uses, stratified silicates, such as a bentonite, are preferably dosed in a dispersed form. This is done, for example, in the case of paper production in view of an agglutination of disturbing substances or in the use in the case of formulations of washing agents. Thus, a bentonite is used as a so-called retention agent during a paper production process.

The addition of a bentonite to formulations of washing agents in powder form serves to lift the soft touch of the washed clothes. This conception also extended to liquid washing agents, in which cases, also by adding a bentonite, the soft touch of the washed clothes should be increased.

For the technical uses described above, it is of interest to make available a bentonite in a dispersed form, such that the content of solid materials of the bentonite is especially high in the aqueous suspension or respectively in the colloidal solutions. However, a production of such highly concentrated thick suspensions is not possible without problems, since eg bentonites typically form gels in an aqueous colloidal solution. This effect is technically used, among other things, also in the case of the use of bentonites in thickening agents. The mechanisms of the formation of gels in a bentonite are described, among other places, in the publication of S. Abend and G. Lagaly, Applied Clay Science 16 (2000) pages 201-227.

U.S. Patent Document US 5,484,834 discloses a thick liquid suspension of bentonite, which contains water, a polyacrylate and a sodium salt of silicic acid. The thick bentonite suspension otherwise contains a sulphonate in a proportion of 10-30% by weight. By the high concentration of a dispersing agent, which is between 10 and 30%, as well as by the presence of a sodium silicate, whereby the thick suspension is alkalized, they cannot be used for formulations, whose values of pH are located in the neutral region.

International patent application document WO 93/22254 discloses concentrated thick suspensions of bentonites and a process for their production. In this case, at least 8% by weight of the bentonite is contained in the concentrated aqueous thick suspension of bentonite. The low viscosity is adjusted by the addition of salts. In this context, in the case of the first of the salts, these are sodium and lithium compounds with anions taken from all those of chloride, carbonate, nitrate, citrate, sulfate, acetate or phosphate, which are added individual way or in a combination between them. In the case of the second saline component, these are potassium salts and anions taken from all those of chloride, carbonate, nitrate, citrate, sulfate, acetate or phosphate, or respectively sodium silicate, sodium pyrophosphate or of a sodium polyacrylate having a low molecular weight. Such a formulation has the disadvantage that it is not compatible with liquid formulations of washing agents, since the high proportion of electrolytes can destroy or influence the gel phases.

European patent application document EP 0 485 124 A1 discloses an inflatable clay of bentonite, which is used for the paper production process as a liquid concentrated material containing at least 15% of a bentonite. The high concentration of bentonite is achieved by the addition of an electrolyte. As such electrolyte, monovalent ion salts are used, in particular sodium and ammonium salts. These are those taken among all the compounds of chlorides, sulfates or carbonates. Thick suspensions with a concentration of bentonite of 9-30% by weight can be adjusted. For use in the paper production sector, these thick suspensions must be diluted later. In the case of electrolytes, sodium or ammonium salts of the corresponding chloride, sulfate or carbonate compound are predominantly used. The use is possible only in the paper production sector, but not in the washing agents sector.

WO 95/09135 discloses a highly concentrated and stabilized thick suspension of a smectite having a low viscosity, and a production process for it. This thick suspension contains between 10 and 47% by weight of a smectitic clay. By adding amines of low molecular weight (at least 0.3% by weight), the swelling of the clay is prevented and the solid material content of the thick suspension is increased. The use of such amines restricts the use of this thick suspension, since the amines can interact with the anionic surfactant system. For incorporation of a thick suspension of bentonite in washing agent formulations, it would therefore be advantageous to work without any amine. WO 95/09135 mainly describes uses that refer to the production of paper and / or as thickening agents.

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

E06762361

11-12-2014

In US 4,916,094 a process for the treatment of a raw kaolin mineral is described, realizing that:

a) the clay is kneaded with a sufficient amount of water, so that an aqueous sludge with a solid material content of at least 60% by weight is obtained, the pH value of the sludge is adjusted by an addition of ammonia , at a value in the range of about 3.0 to 4.5, and a poly (acrylic acid) is added as a dispersing agent in such a proportion that a low shear viscosity is adjusted;

b) coarse particles are separated from the sludge;

c) the sludge is bleached with a reducing bleaching agent, and

d) a clarified mud is obtained from a clay with an improved coloration, which has a solid material content of at least 60% by weight.

US 5,104,551 describes a procedure for the precipitation of clays containing phosphates from sewage sludges, which are formed by leaching phosphate ores, which can also be applied in the case of low pH values and in organic solvents. As a precipitation agent, a mixture of a poly (ethylene oxide) (with a molecular weight> 5,000,000) and a hydroxypropylcellulose (with a molecular weight> 1,000,000) is proposed, which additionally can also still contain a poly (ethylene glycol ).

In US 4 476 029 A there are described improved dispersing agents for the production of drilling fluids containing bentonite, which contain an agent intended for the control of water loss as well as a serious agent. A dispersing agent is used as a dispersing agent that is stable at high temperatures, containing a poly (acrylic acid) with a molecular weight in the range of about 4,000 to 8,000.

TO . Alemdar et al., In the Journal of Materials Science 40 (2005) 171-177 describe research on the effect of a poly (ethylene glycol) on the fluidity behavior of bentonite sludge that has been activated with sodium carbonate. After the addition of a PEG (poly (ethylene glycol)) manifest modifications of the rheological properties were observed.

US 5,629,368 describes a process for the production of liquid bentonite sludges, which are advantageously used as dehydration agents and retention aids and containing between 0.1 and 10% of the sodium salt of a silicic acid as well as they have a content of 15 to 35% of a bentonite. In addition to the sludge, a glycol has been added, such as propylene glycol or ethylene glycol, as well as a copolymer based on acrylic acid and maleic acid.

The thick suspensions described in the prior art have, however, certain disadvantages, so that there is a constant need for improved thick suspensions having a high content of stratified silicates and good storage stability.

The invention was therefore based on the mission of developing additive conceptions for the production of highly concentrated thick suspensions, which can be used for a large number of stratified silicate types such as bentonites, eg bentonites of calcium, magnesium bentonites and mixed calcium and sodium bentonites, and that are appropriate for the production of thick suspensions that are stable in storage for a long period of time. Another mission of the present invention is also to make available a thick suspension or respectively a sludge that is based on stratified silicates with a high content of solid materials, and that avoids the disadvantages of the prior art.

The problem posed by this mission is solved according to a first aspect of the invention by a thick suspension or respectively a sludge containing

a) at least 10% by weight, based on the total content of the slurry suspension or, respectively, of the sludge, of a stratified silicate that is chosen from the group of smectites, chosen from the set consisting of montmorillonites such as a bentonite and a batan land, a hectorite, an antigorite, a nontronite, a beidellite, a saponite, from the whole of the vermiculites, from the set of the illites or from the micas, as well as a sepiolite, an attapulgite (paligorskita), a estevensite or a chlorite;

b) an aqueous suspension medium;

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

E06762361

11-12-2014

c) an auxiliary dispersion agent, which is chosen from at least one poly (ethylene glycol) having an average molecular weight of less than 90,000.

Thus, it was surprisingly found that by means of the preceding auxiliary agents of dispersion in thick suspensions having a high content (10% by weight or more) of a stratified silicate, problems, which appear in the state of the art, are avoided , of an increase in the viscosity or respectively of the formation of a gel, and that thick, highly concentrated and storage stable suspensions can be made available.

Especially preferably, in this case the thick suspension or respectively the sludge, together with components a), b) and c), does not have any components containing monovalent metal cations. Thus, one aspect of the invention is based, among other things, on the recognition that the use to reduce the viscosity of certain salts in particular of lithium and sodium salts is problematic when dispersing stratified silicates such as bentonites , in particular in the form of calcium and / or magnesium, as well as stratified silicates having a high calcium and / or magnesium content. If monovalent ions are added in this context to disperse stratified silicates such as bentonites, in particular in the forms of calcium and / or magnesium as well as stratified silicates having a high content of calcium and / or magnesium. If monovalent ions are added in this context to effect dispersion, then an increase in viscosity is first found, which is conditioned by the fact that monovalent ions can activate bentonite by means of an exchange for divalent cations of the intermediate layers. Likewise, the use of alkali metal salts of polyacrylates, as described, for example, in WO 95/09135, also does not lead in this case to the goal sought, since an activation appears the same as in the case of simple inorganic salts. Thus, it can certainly be verified in the first place that, in the case of the use of alkali metal salts of polyacrylates to disperse bentonites, thick suspensions result in a low viscosity, but after a period of time 1-3 days of storage, however, they have thickened to form a macroscopic gel.

A stratified silicate can be, for example, a two-layer or three-layer silicate, natural or synthetic. As a three-layer silicate, those taken from the group of smectites (such as a montmorillonite, a hectorite, an antigorite, a nontronite, a beidellite or a saponite) and vermiculite, illite or micas are used.

Other stratified silicates used are a sepiolite, an attapulgite (paligorskite), an estevensite or a chlorite. Among the minerals that contain montmorillonite, mention should be made in particular of a bentonite and a battan earth, which may be composed in a different way depending on the site.

The layered silicate may have been chemically and / or thermally modified. A chemical modification means in particular an activation with inorganic and / or organic acids. In the case of inorganic acids, for example, hydrochloric acid, phosphoric acid or sulfuric acid should be mentioned.

The heat treatment includes desiccation and eventually a calcination. This heat treatment can be carried out under oxidizing or reducing conditions.

According to a preferred embodiment according to the invention, in the case of stratified silicates it is at least one smectitic stratified silicate. More preferably, selected stratified silicates taken from the assembly consisting of a bentonite, a hectorite, a saponite or a beidellite are used.

According to an embodiment according to the invention, which is especially preferred, in the case of the stratified silicate used it is a stratified silicate containing divalent cations, in particular alkaline earth metal cations such as calcium ions and / or magnesium. What is to be understood by this concept is usual for an expert in the specialty. The presence of divalent cations in the stratified silicate can be determined, for example, by elementary analysis. According to a particularly preferred embodiment, it is a layered calcium-containing silicate.

According to another preferred embodiment, a part of the cation exchange capacity (in English Cation Exchange Capacity, with the acronym CEC) is formed by divalent or multivalent cations, in particular alkaline earth metal cations such as calcium and / or magnesium ions, in particular calcium ions. Some procedures for the determination of CEC as well as the proportions of individual ions are indicated below.

Thus, it was surprisingly found that the problems, which appear in the state of the art in the case of such stratified silicates, of an increase in viscosity or respectively of the

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

E06762361

11-12-2014

gel formation and highly concentrated thick suspensions that are stable in storage can be made available.

According to another preferred embodiment according to the invention, in the case of at least one stratified silicate it is a stratified silicate that is capable of swelling. The swelling capacity of at least one stratified silicate is preferably located in at least 4 ml / 2 g. The ability to swell can be determined as indicated in the following part of methods. In this context it should be mentioned that eg stratified silicates containing calcium or magnesium (pure) are also capable of swelling. By exchanging divalent cations of intermediate layers with monovalent cations, the layered silicate is swollen in aqueous suspensions or thick suspensions.

Two or more stratified silicates can also be used for the thick suspension or respectively for the sludge. The terms "thick suspension" and "sludge" are understood within the scope of the present invention in a broad sense and with the same meaning and should cover any type of dispersion or suspension of at least one silicate stratified in a liquid medium.

In the context of the present invention it was found, according to a first aspect, that by using at least one poly (ethylene glycol) with a very low molecular weight, as described herein, a sludge or a suspension can be obtained respectively Thickens at least one stratified silicate, which is highly concentrated and stable in high grade storage.

As mentioned above, preferably a component containing monovalent metal cations (or ammonium ions) is added to components a), b) and c) in the case of the production of the thick (concentrated suspension) ). Preferably, neither the aqueous suspension medium (component b) contains monovalent metal cations (nor ammonium ions). The same is preferably valid for the dispersal auxiliary agent itself (component c)). It was surprisingly found that strong swelling and gelation of at least one stratified silicate can be avoided in this way.

Advantageously, with the thick suspension or respectively with the sludge according to the invention, stratified silicates such as bentonites can be made available in storage in a highly concentrated aqueous dispersion, the dispersions still being suitable for pumping. and the viscosity behavior remaining stable in storage over a period of several days and several weeks.

In the context of the invention it was also found that the aqueous suspensions have especially advantageous (small) viscosities and high storage stability, when the pH value of the thick suspension is between about 4 and 10, in particular between about 5, 5 and 9, more preferably between about 6 and 9, particularly preferably between about 6.5 and 8.5. If this pH value is not established without problems by mudding the at least one stratified silicate in the aqueous suspension medium, eventually after adding the auxiliary dispersing agent (component c)), the adjustment of the preceding Preferred pH ranges can be effected by the addition of at least one acid. In this case, arbitrary inorganic or organic acids can be used in principle. In particular, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid or nitric acid can be used without being limited thereto. Within the organic acids, for example, citric acid, oxalic acid, formic acid, acetic acid and the like can be mentioned. Especially preferred is hydrochloric acid.

According to an embodiment that is preferred according to the invention, those acids whose anions act on the Ca2 + or Mg2 + forming complexes in a bad way or not at all are used. In this way, a solution extraction of the Ca2 + or Mg2 + from the stratified silicate can be minimized further, and consequently an activation or thickening of the thick suspension respectively.

According to the invention, it is otherwise preferred that as long as the addition of an acid is carried out, the acid is previously arranged for the adjustment of the expected pH value in the aqueous suspension medium, and then the addition of the at least one stratified silicate.

According to a preferred embodiment according to the invention, the slurry or sludge respectively has a content of monovalent metal cations (and ammonium ions) of less than about 0.5% by weight, in particular less than 0.1% by weight, preferably less than 0.05% by weight, more preferably less than 0.01% by weight, the ion content of at least one stratified silicate It was surprisingly found that by means of such a (small) content of monovalent metal cations (and ammonium ions) a low viscosity is possible in the case of high concentrations of stratified silicates and storage stability

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

E06762361

11-12-2014

especially good According to a particularly preferred embodiment, the thick suspension or respectively the sludge according to the invention does not contain, together with component a), any component containing monovalent metal cations (and ammonium ions), not being taken into consideration usual impurities containing the preceding cations, in particular sodium ions, in commercially used products, which are used in accordance with the invention as an auxiliary dispersion agent according to the invention (component c)). In accordance with another preferred embodiment of the present invention, it has been found that the dispersion auxiliary agents employed in accordance with the invention provide especially favorable results, when the proportion of divalent cations in the CEC of at least one silicate Stratified is at least 35%, in particular at least 40%.

In addition, it is preferred according to the invention that in the case of the divalent cations of the at least one stratified silicate, it is calcium and / or magnesium ions. For the rest, it is preferred that the proportion of monovalent metal cations (and ammonium ions), in particular sodium ions in the CEC of at least one stratified silicate is less than about 65%.

According to yet another preferred embodiment according to the invention, the CEC of the at least one stratified silicate is located in more than 70 meq / 100 g, preferably in at least 75 meq / 100 g. A procedure for the determination of the CEC is indicated below.

According to the invention, highly concentrated thick suspensions of at least one stratified silicate can be produced. In such a case, the content of the thick suspension in terms of at least one stratified silicate is preferably located in more than 10% by weight, in particular in more than 15% by weight, more preferably in more than 20 % by weight, even more preferably more than 30% by weight, and particularly preferably more than 40% by weight.

As an aqueous suspension medium, water is used according to the invention, especially preferably. However, other aqueous suspension media such as, for example, an aqueous-alcoholic solution or an aqueous solution containing glycols can also be conceived.

According to one aspect of the present invention, at least one poly (ethylene glycol) (= polyglycol) with a relatively lower average molecular weight is used as an auxiliary dispersion agent. Thus, it was surprisingly found that in the case of the use of such poly (ethylene glycols) with a relatively lower average molecular weight, thick suspensions with a high content (10% by weight or more) of a stratified silicate can be obtained , which make it possible to avoid the problems of an increase in viscosity or gel formation respectively and make possible highly concentrated thick suspensions that are stable in storage. This is not possible with poly (ethylene glycols) having an essentially higher average molecular weight, eg above 100,000, which are used in the state of the art as flocculating agents (and precisely not as dispersing agents ). Such flocculating agents are used in order to bind individual particles of stratified silicates through a so-called "bridging flocculation", and consequently increase the viscosity. According to an especially preferred embodiment according to the invention, at least one poly (ethylene glycol) having an average molecular weight of less than about 80,000, in particular less than about 70,000, in particular between about 200 and about 50,000, preferably between about 2,000 and 20,000, more preferably between about 4,000 and 15,000, more preferably between about 4,000 and 12,000.

According to a preferred embodiment according to the invention, at least one poly (ethylene glycol) is used in a proportion comprised between approximately 0.1 and 10% by weight, in particular between approximately 2 and 8% by weight, in case referred to at least one stratified silicate. In individual cases, smaller or larger amounts may also be convenient.

As explained above, in the context of the present invention it was surprisingly found that, unlike the auxiliary agents of dispersion (electrolytic) that have been described in the state of the art and that compositions containing cations of monovalent metals, the dispersion auxiliary agents according to the invention can be used in a particularly advantageous way for the production of highly concentrated and storage stable thick suspensions.

A further aspect of the present invention relates to a process for the production of a thick suspension or respectively of a sludge as described herein. In this case, at least one stratified silicate is preferably made available, preferably in the form of particles or powders. Otherwise, an aqueous suspension medium is described as described above, and an auxiliary dispersion agent is made available as described above. The thick suspension according to the invention is then produced by mixing the preceding components (components a) -c)). In such a case, it was surprisingly found that thick suspensions or sludges can be produced that are especially stable in storage, when firstly it is previously disposed in the aqueous medium.

fifteen

twenty

25

30

35

40

Four. Five

fifty

E06762361

11-12-2014

suspension the at least one dispersion auxiliary agent, and then the at least one stratified silicate is added. Moreover, in order to obtain thick suspensions that are especially stable in storage, it is preferred that, as long as an acid is used for the adjustment of the preferred pH range described above, it is previously arranged in the aqueous suspension medium, before the at least one stratified silicate is added.

A further aspect of the present invention relates to the use of at least one poly (ethylene glycol) as described herein, as an auxiliary dispersion agent for at least one stratified silicate, in particular at least one stratified silicate which It contains calcium and / or magnesium.

A further object of the present invention is the use of aqueous suspensions or sludge, in particular with a content of at least 10% by weight of a layered silicate. These can be used in particular for washing and cleaning agents, such as, for example, the incorporation of bentonite in liquid formulations of washing agents or in liquid formulations of softening agents. In addition to this, in another additional use according to the invention, thick suspensions or sludge respectively can be used for paper use, in this case in particular in the field of repression of disturbing substances and retention agents. However, other uses of the thick suspension according to the invention in other sectors, in which the use of thick suspensions of highly concentrated stratified silicates is advantageous, can be conceived and covered by the present invention. In another additional use according to the invention, thick suspensions or sludges are replaced in all sectors, in which stratified silicates such as bentonites are used as sorption agents or respectively adsorbents or thickeners.

The invention is explained in more detail below with the help of the following non-limiting examples.

Examples / measurement methods

Determination of cation exchange capacity (CEC)

Principle: The clay is treated with a large excess of an aqueous NH4Cl solution, then washed off and the amount of NH4 + that has remained on the clay is determined by elemental analysis.

Me + (clay) - + NH4 + -NH4 + (clay) - + Me +

(Me + = H +, K +, Na +, 1/2 Ca2 +, 1/2 Mg2 + ....)

Apparatus: A sieve, 63 µm; a 300 ml frosted neck Erlenmeyer flask; an analytical scale; a 400 ml membrane Büchner funnel; a cellulose nitrate filter, 0.15 µm (from the Sartorius entity); a drying cabinet, a reflux refrigerant; a heating plate, a distillation unit, VAPODEST-5 (from the Gerhardt entity, no. 6550); a volumetric flask, 250 ml; an AAS (atomic absorption spectrometry) with flame.

Chemicals: a 2 N solution of NF4Cl; Nessler's reagent (from Merck, article no. 9028); a 2% boric acid solution; a lye of soda, 32%; a 0.1 N hydrochloric acid; a 0.1% NaCl solution; a solution of KCl, 0.1%.

Embodiment: 5 g of a clay are screened through a 63 µm sieve and dried at 110 ° C. Then exactly 2 g are weighed on an analytical scale by differential weighing, they are introduced into the Erlenmeyer flask with a ground neck and combined with 100 ml of a 2 N NH4Cl solution. The suspension is boiled at reflux for one hour. In the case of bentonites that contain a large amount of CaCO3, an evolution of ammonia can be achieved. In these cases, a solution of NH4Cl should be added for so long until no smell of ammonia can be perceived. An additional check can be carried out with a wet indicator paper. After a period of permanence of approximately 16 h, the bentonite with NH4 + is filtered off through a Büchner funnel with membrane and washed with fully desalinated water (approximately 800 ml) until the broad ion exemption is obtained. The ion exemption detection of the wash water is carried out to detect NH4 + ions with the Nessler reagent that is sensitive to them. The number of washes may vary, depending on the type of clay, between 30 minutes and 3 days. The clay with NH4 + that has been washed away is removed from the filter, dried at 110 ° C for 2 h, ground, sieved (in a 63 µm sieve) and again dried at 110 ° C for 2 h. After this the NH4 + content in the clay is determined by elementary analysis.

Calculation of the CEC: The CEC of the clay was determined in a usual way through the NH4 + content in the clay with NH4 +, which had been ascertained through an elemental analysis of the N content.

10

fifteen

twenty

25

30

35

E06762361

11-12-2014

the Vario EL 3 apparatus of Elementar-Heraeus entity, from Hanau, Germany, according to the manufacturer's instructions. Data are given in mval / 100 g of clay (meq / 100 g). Example: nitrogen content = -0.93%; Molecular Weight: N = 14.0067 g / mol

image 1

CEC = 66.4 meq / 100 g of bentonite with NH4 +.

Determination of swelling volume

The swelling volume is determined as follows:

A calibrated graduated cylinder with a capacity of 100 ml is filled with 100 ml of distilled water. 2.0 g of the substance to be measured are slowly added in portions of 0.1 to 0.2 g on the surface of the water. After the sinking of the material, the following amount is added. After the addition is finished, wait for 1 hour and then read the volume of the swollen substance in ml / 2 g.

Viscosity measurements

Viscosity measurements carried out in the following manner were carried out with a Brookfield digital DVII model viscometer (from Brookfield, Stoughton, MA 02072, USA). The data (eg in mPas) for the spindles and the revolutions that had been used are indicated in each case in the Examples.

Thick suspension production

For this, a PENDRAULIK agitator (from FH Pendraulik, Springe, Germany) was used. The additives were first introduced in each case with stirring in the water. The bentonite was then introduced with stirring with the Pendraulik stirrer in position 1 (930 rpm (revolutions per minute)) for up to 5 min. It was subsequently stirred for 5 min., In the 1.5 position (15 rpm). Thick suspensions occurred in this case normally in beakers with a capacity of 800 ml. In the case of the 500 ml batches, small toothed discs (with diameters of 40 mn) were used as a stirring tool. In the case of the 5 l batches, a dissolving disk with a diameter of 50 mm was used as a stirring tool. A bucket with a capacity of 10 l was used.

Additives according to the invention

Poly (ethylene glycols) 1500, 4000, 6000, 20000 were acquired from the CLARIANT entity of Frankfurt under the trade name of Polyglycol. Alternatively, poly (ethylene glycols) of the BASF entity that are marketed under the trade name of Pluriol were also used. The manufacturers of the individual PEGs are indicated in each case in the Examples.

Other additives and chemicals

As a typical suitable protonated acrylate, Sokalan CP 1OS from BASF AG Ludwigshafen was used, which is presented as a 40% solution by weight. hydrochloric acid: 0.5 m, from Riedel del Haen or Merck Dispex® N40, A40: Auxiliary dispersing agent from Ciba, Grenzach (aqueous solutions are used in the manner in which they were purchased from the manufacturer)

E06762361

11-12-2014

Example 1 For the production of thick suspensions, a bentonite (Bentonite 1) was used with the following properties:

Property

Value

Montmorillonite content (according to the methylene blue method)

75%

Secondary mineral content (X-ray measurements) Quartz + cristobalite Feldspar

<5% by weight <12% by weight

Cation exchange capacity

75 meq / 100 g

Proportion of Na + in the CEC

twenty %

Two different variants of Bentonite 1 were used: Table A: Screening residues

Property

Variant 1 Variant 2

Dry sieving residue at: 45 µm (% by weight)

<0.3% 14%

Wet sieving residue at: 45 µm (% by weight)

<0.3% 9.5%

From the above-mentioned bentonites, thick suspensions with 25% by weight of a solid material, referred to dry bentonite, were produced in each case (which is determined by a determination of the water content after drying until reaching to the constancy of weight at 130 ° C) and these were characterized in regard to their viscosity.

Variant 2 (with other fineness of particles) did not show large differences in the obtained viscosities.

Table 1:

25% by weight of Bentonite 1, variant 1, with 5% Polyglykol 4000

Viscosity measurement (after the production of the thick suspension)

Spindle 3

5 rpm

3,000

50 rpm

680

Spindle 5

5 rpm

3,900

20 rpm

1,480

100 rpm

600

PH value

8.4

As Table 1 shows, Polyglykol 4000 was appropriate in order to produce concentrated suspensions.

In another test, therefore, the pH value of the thick suspension was adjusted to 7 with hydrochloric acid. Acid,

After dissolution of the poly (ethylene glycol), it was previously placed before the addition of the bentonite.

Table 2a:

25% by weight of Bentonite 1, variant 1, with 5% Polyglykol 4000, the pH value is adjusted to 7 with hydrochloric acid

Viscosity measurement

New After 1 day

Spindle 3

5 rpm

3,220 7,740

50 rpm

390 900

Spindle 5

5 rpm

3,440 8,560

20 rpm

940 2,220

100 rpm

240 520

PH value

7.4 7.5

In order to achieve a particularly good storage capacity of the thick suspensions, it was advantageous to previously dispose of the hydrochloric acid, and not to add it later.

E06762361

11-12-2014

As a comparison, measurements were carried out with 2 commercially dispersing agents of the CIBA entity (from Grenzach), the Dispex® N40 and A40 products.

Table 3:

25% by weight of Bentonite 1, variant 1, with 5% Dispex® N40 or respectively 5% A40. as additive

Viscosity measurement

New After 1 day

Spindle 3

N 40 At 40 N 40 At 40

5 rpm

920 220 n.m. n.m.

50 rpm

574 224 n.m. n.m.

Spindle 5

5 rpm

1,120 240 n.m. n.m.

20 rpm

820 260 n.m. n.m.

100 rpm

692 270 n.m. n.m.

PH value

8.1 8.0 n.m. n.m.

n.m. = not measurable

5 In the case of these additives, the concentration was varied between 0.2 and 5%. In all cases, thick suspensions with low viscosity were first obtained, which nevertheless gelled after 1 day. As an example, Table 3 shows the values for thick suspensions with 5% of an additive.

Example 2

With Bentonite 1 according to variant 1 of Example 1, the influence that was investigated at a pH value of 7

10 had the molecular weight of poly (ethylene glycol) over viscosity. In that case the molecular weight was varied between 600 and 20,000 g / mol.

Table 4

Suspensions with 25% by weight of Bentonite 1, variant 1, with Pluriol 600 (from BASF) as an additive

Viscosity measurement

New After 1 day After 14 days

Spindle 3

5 rpm

4,240 10,300 16,800

50 rpm

474 1,060 1,680

Spindle 5

5 rpm

4,800 10,100 17,000

20 rpm

1,260 2,560 4,360

100 rpm

296 588 -

PH value

6.9 7.4 -

Table 5:

The same system as in Table 4: with 5% Polyglykol 1500 (from Clariant) as an additive

Viscosity measurement

New After 1 day After 14 days

Spindle 3

5 rpm

3,760 8,400 14,200

50 rpm

418 900 1,510

Spindle 5

5 rpm

4,080 8,320 14,200

20 rpm

1,100 2,100 3,780

100 rpm

252 504 820

PH value

6.9 7.3 -

Table 6:

The same system as in Table 4: with 5% Polyglykol 6000 (from Clariant) as an additive

Viscosity measurement

New After 1 day After 14 days

Spindle 3

5 rpm

3,240 6,440 10,200

50 rpm

370 710 1,140

Spindle 5

5 rpm

3,440 6,480 10,200

20 rpm

940 1,740 2,480

100 rpm

224 408 600

PH value

6.7 7.3 -

E06762361

11-12-2014

Table 7

The same system as in Table 4: with 5% Polyglykol 20000 (from Clariant) as an additive

Viscosity measurement

New After 1 day After 14 days

Spindle 3

5 rpm

3,180 5,680 9,420

50 rpm

388 694 984

Spindle 5

5 rpm

3,360 5,920 9,120

20 rpm

960 1,600 2,400

100 rpm

236 416 556

PH value

6.8 7.3 -

As the preceding Tables 4 to 7 show, poly (ethylene glycols) (PEGs) could be used, over the entire range of molecular weights that had previously been investigated, for stabilization of the

5 bentonite investigated. Comparison of viscosities as a function of molecular weight showed that higher molecular weights lead to low viscosities also after storing the thick suspensions. Longer molecules with the largest average molecular weight were presumably more tightly bound to the surface and intercalated with less force over time between the layers.

10 Example 3

The same bentonite was used according to Example 1, which had been produced by means of an activation with 4.3% sodium carbonate (Bentonite 2). In this way, all the Mg2 + and Ca2 + ions of Bentonite 1 were replaced by sodium ions according to the invention.

It was found that according to the process according to the invention this Bentonite 2 could also be dispersed with

15 poly (ethylene glycols). However, the necessary added amount rose to approximately 10% as a result of the highest specific surface area that had been made available in the dispersion. The results of the viscosity measurements in the recently prepared thick suspensions are shown in Table 8, being able to observe a strong increase in viscosity after a few days.

Table 8

Characteristic data of the viscosity of thick suspensions from Bentonite 2 (25% by weight) with 10% Polyglykol 4000

Viscosity measurement

Spindle 3

5 rpm

4,280

50 rpm

706

Spindle 5

5 rpm

5,280

20 rpm

1,540

100 rpm

464

PH value

9.8

20 Example 4 (reference example)

Bentonite, variant 1, prepared according to Example 1, was dispersed in another formulation according to the invention with an acidic polyacrylate, Sokalan® CP 10 S of the BASF entity. Also with this additive, thick suspensions could be produced by means of additions in the range of eg percentages of 0.5 to 5%

25 stable in storage with a concentration of bentonite of 25% by weight.

In the following, the Brookfield viscosities with the spindle 5 at 100 rpm are shown as an example, as well as the complete viscosity data in the case of a 1% addition. The data of the additions refer to the aqueous solution of Sokalan CP 10S, as obtained commercially).

30 Table 9

Viscosities with 25% Bentonite 1 and 1 and 2% Sokalan CP10S (spindle 5 100 rpm)

Sokalan concentration CP10S% by weight based on bentonite

Immediately After 1 day

2.5

44 156

one

48 328

E06762361

11-12-2014

Table 10

Complete viscosity data of the thick suspension with 1% by weight of Sokalan CP 10S

Viscosity measurement

New After 1 day

Spindle 3

5 rpm

0 300

50 rpm

52 326

Spindle 5

5 rpm

0 320

20 rpm

0 300

100 rpm

48 328

PH value

6.6 7

As a comparison, the corresponding Na salt ((Sokalan® CP 10) was tested as an additive. Certainly, in this case, low viscosities could similarly be determined directly after preparation, as for the use of Sokalan® CP 10S, but The thick suspension gelled after one day to form a gel that was no longer pourable.

Table 11

Viscosity data for a batch analogous to Tables 9 and 10, but Sokalan® CP 10S (Na salt) was used instead of Sokalan® CP 10 S

Viscosity measurement

New After 1 day

Spindle 3

5 rpm

120 No measurement was possible because of the formation of gels

50 rpm

140

Spindle 5

5 rpm

160

20 rpm

160

100 rpm

156

PH value

8.2

10 These data showed that polyacrylates in the acid form (protonated form) that had been used had considerable advantages. The use of a sodium form leads to thickening through an activation with Na of bentonite. Surprisingly, this effect did not appear in the case of the acid form.

Example 5 Two other bentonites were used, whose different properties are listed below: Table 12

Properties of the two bentonites used

Property

Unity Bentonite 3 Bentonite 4

Montmorillonite content (according to methylene blue method)

[%] 94 100

Secondary mineral contents (x-ray measurements) Quartz and cristobalite Calcite Feldspar

[% in weigh] <3 - eleven -

PH value in the case of 5% by weight

8.5 9

Cation exchange capacity

meq / 100 g 95 110

Proportion of Na in total cation exchange capacity

[%] 56 32

Screening wastes

Dry sieving residue at 45 µm

[% in weigh] 2.5 9.8

45 µm wet sieve residue

[% in weigh] 2.0 2.5

E06762361

11-12-2014

Example 6 (reference example) Bentonite 3 from Example 5 was investigated as regards the production of highly concentrated thick suspensions. Table 13

Viscosity data of Bentonite 3 with different additive contents (polyglycols (PEG) and Sokalan® CP 10 S

Additive

Content [% by weight] PH value Storage time period Viscosity Brookfield Spindle 5

20 rpm

100 rpm

Polyglykol

2.5 8.1 0 1 day 2,700 6,650 700 1,670

5

8.2 0 1 day 2,460 5,600 676 1,520

Sokolan CP 10S

one 5.7 0 1 day 300 1,640 316 1,980

2.5

4.7 0 1 day 380 1,640 700 960

5 The data in Table 13 showed that with the additives according to the invention Bentonite 3 could be formulated as a thick suspension or respectively as a sludge in high concentration. Despite the different percentage proportions of poly (ethylene glycol) or polyacrylate respectively, the tests showed that storage stability was still present and there was no sludge gelation.

10 Example 7 (reference example)

As another variant, the production of a thick suspension with Bentonite 4 of Example 5 was investigated. This was also used in a concentration of 25% by weight, based on the dry substance.

Table 14:

Viscosity data of Bentonite 4 with different additive contents (polyglycols (PEG) and Sokalan® CP 10 S

Additive

Content [% by weight] PH value Storage time period Viscosity Brookfield Spindle 5

20 rpm

100 rpm

Polyglykol 400 + hydrochloric acid

5 + 16% 7.0 7.5 0 1 day 3,540 5,400 832 1,210

Sokalan CP 10S

one 7.2 0 1 day 780 - 480 -

2.5

6.2 0 1 day 440 6,200 364 2,400

The data in Table 14 show that the sludges according to the invention maintained their positive properties also in the case of a use of another bentonite (Bentonite 4). For the achievement of good and stable viscosities, the pH value was preferably adjusted to values <8.

Example 8

As another variant, it was tried according to Example 1 (see also Table 1) to produce a thick suspension, however using poly (ethylene glycols) with an average molecular weight of more than 100,000. For example, PEGs with an average molecular weight of 400,000 (Polyol ™ WSR N 3000 and Polyox ™ WSR 301, from Dow Chemical Company) were used. In this case, no thick vertible suspension could be obtained but only a solid mass. This can be explained by the fact that high molecular weight PEGs can bind by

25 bridging flocculation to individual bentonite particles and therefore cannot act by reducing the viscosity by stereo stabilization.

Claims (24)

5 10 fifteen twenty 25 30 35 40 Four. Five E06762361 11-12-2014

one.

Thick suspension or mud respectively, which contains

a) at least 10% by weight of at least one stratified silicate that is chosen from the group of smectites, chosen from the set consisting of a montmorillonite such as a bentonite and a battan earth, a hectorite, a antigorita, a nontronita, a beidellita, a saponita, of the whole of the vermiculites, of the set of the illitas or of the micas, as well as a sepiolite, an attapulgite (paligorskita), a stevensite or a chlorite, referred to the total weight of the thick or respectively sludge suspension; b) an aqueous suspension medium; c) an auxiliary dispersion agent that is chosen from at least one poly (ethylene glycol) having an average molecular weight of less than 90,000.

2.

 Thick suspension according to claim 1, characterized in that the at least one poly (ethylene glycol) has an average molecular weight of less than about 80,000, in particular less than about 70,000, in particular between about 200 and about 50,000, of preferably between about 2,000 and 20,000, more preferably between about 4,000 and

3.

Thick suspension according to one of the preceding claims, characterized in that the proportion of divalent cations in the CEC of at least one stratified silicate is at least 30%, in particular at least 40%.

Four.

Thick suspension according to one of the preceding claims, characterized in that the thick suspension or sludge, together with components a), b) and c), does not have any component containing monovalent metal cations.

5.

Thick suspension according to one of the preceding claims, characterized in that the pH value of the thick suspension is between about 5 and 10, in particular between about 6 and 9, more preferably between about 6.5 and 8, 5.

6.

Thick suspension according to one of the preceding claims, characterized in that the pH value according to claim 5 is adjusted by the addition of at least one acid.

7.

Thick suspension according to one of the preceding claims, characterized in that in the case of at least one stratified silicate it is a stratified silicate capable of swelling.

8.

Thick suspension according to one of the preceding claims, characterized in that in the case of at least one stratified silicate it is a stratified silicate containing calcium.

9.

Thick suspension according to one of the preceding claims, characterized in that in the case of at least one stratified silicate it is a smectitic stratified silicate.

10.

Thick suspension according to one of the preceding claims, characterized in that the content of monovalent metal ions and ammonium ions, in particular the sodium content, of the thick suspension is located at a value smaller than 0.5% by weight, in particular smaller than 0.1% by weight, preferably smaller than 0.05% by weight, more preferably smaller than 0.01% by weight, the content not being included in the calculation of at least one stratified silicate in terms of monovalent metal ions and ammonium ions, in particular sodium ions.

eleven.

Thick suspension according to one of the preceding claims, characterized in that in the case of at least one stratified silicate it is calcium and / or magnesium ions.

12.

Thick suspension according to one of the preceding claims, characterized in that the proportion of monovalent cations, in particular of sodium ions in the CEC of at least one stratified silicate is less than 65%.

13.

Thick suspension according to one of the preceding claims, characterized in that the CEC of at least one stratified silicate is located in more than 70 meq / 100 g, preferably in a value greater than or equal to 75 meq / 100 g .

15,000 14 5 10 fifteen twenty 25 30 E06762361 11-12-2014

14.

Thick suspension according to one of the preceding claims, characterized in that the content of the thick suspension in terms of at least one stratified silicate is located in more than 15% by weight, in particular in more than 20% by weight, of more preferably more than 30% by weight, particularly preferably more than 40% by weight.

fifteen.

Thick suspension according to one of the preceding claims, characterized in that in the case of the aqueous suspension medium it is water, an aqueous-alcoholic solution or an aqueous solution containing glycols.

16.

Thick suspension according to one of the preceding claims, characterized in that at least one poly (ethylene glycol) is used in a proportion comprised between approximately 0.1 and 10% by weight, based on at least one stratified silicate, in particular from about 2 to 8% by weight.

17.

Process for the production of a thick suspension or respectively of a sludge according to one of the preceding claims, characterized in that, in the first place, the at least one dispersion auxiliary agent is previously arranged in the aqueous suspension medium, optionally mediating the addition of an acid for the adjustment of the pH value, and then the at least one stratified silicate is added.

18.

 Use of at least one poly (ethylene glycol) with an average molecular weight of less than 90,000 as an auxiliary dispersion agent for at least one stratified silicate in the case of the production of a thick suspension or respectively of a sludge, containing at least 10% by weight of the at least one stratified silicate.

19.

Use according to claim 18, characterized in that the proportion of divalent cations in the CEC of at least one statized silicate is at least 30%, particularly at least 40%.

twenty.

Use according to claim 18 or 19, characterized in that in the case of at least one stratified silicate it is a stratified silicate capable of swelling.

twenty-one.

Use according to one of claims 18 to 20, characterized in that in the case of at least one stratified silicate it is a stratified silicate containing calcium.

22

Use of the slurry or sludge according to one of claims 1 to 16, in liquid compositions of washing or cleaning agents, in particular in liquid compositions of washing agents and softeners.

2. 3.

Use of the slurry or sludge according to one of claims 1 to 16, in the paper industry sector, in particular in the case of repression of disturbing substances or in retention agents, or as a thickening or adsorbent agent .

fifteen